World’s tiniest scales

Measuring the contents of a single cell: the nano-machinery of life

Scientists are developing a tiny set of scales that will be capable of weighing each of the 100 million or so different proteins in a human cell.

Dr Michael Roukes from the California Institute of Technology told the ICONN nanotechnology conference in Sydney that his group has designed and made silicon chips bearing several tiny nanotechnology devices that can measure the weight of individual proteins.

“Within the next few years, we can envisage making a chip that can measure millions of individual proteins,” he says.

“It would take roughly ten milliseconds to weigh each molecule,” he says, “meaning it would take just two minutes to measure all of the roughly 100 million proteins in a cell”.

One of the principal goals of Roukes’ work is to use nanotechnology to understand the complete “wiring diagram” of interactions between molecules in individual cells.

Roukes’ dream is that one laboratory could, in a reasonable time, begin to capture multiple snapshots of what these diagrams look like.

Current techniques for doing this combine the contents of many cells, obscuring all but their most obvious inner workings and making today’s efforts to understand biological circuits very labour-intensive.

“A faster technique with single-molecule resolution could have an immense pay-off in terms of allowing scientists to see what is really going on in an individual’s cells, for example, whether they are healthy or diseased,” he says.

“We really are on the cusp of an era in which, instead of understanding the complexity of biochemistry through monumental feats of deductive reasoning, we’ll be able to just go and look at the machinery of life using these nanotech devices.”

This is in keeping with the original vision of Caltech physicist and Nobel Laureate, Richard Feynman, who 50 years ago first envisaged many of the far-reaching implications of nanotechnology.